Vania



Patented June 24, 1919.

J. BECKER. AMMGNIA AND TAR RECOVERY PROCESS.

APPLICATION man lAucmz. 191s.

- ammonium sulfate `that has a high contenty uNrrEr) sra'rEs PATENT 'oEEicE vJOSEPH ABECKIIEL, 0F PITTSBURGH, `PEN'NSYIV'ANIA, ASSIGOR TO THE KOPPERS COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION 0F PENNSYL- VANIA.

AMMONIA .AND ma RECOVERY. PROCESS,

Specification of Letters Patent. Patented June 24, 1919.

Application mea August 12, 191s. serial Nt. 249,378.

To all whom #may concern:

Be it knownthat I, JOSEPH BECKER, a subject of Germany, who have 'declared my intention of becoming a citizen of the `United States, and residing in Pittsburgh, in the county of Allegheny and State of Pennsyl- Vania, have invented a new and useful Improvement in Ammonia and Tar Recovery Processes, of which the following is a specification. M "4 kMy invention relates primarily to the 'recov'ery oftar and of ammonia from roducer-gas and has for its ob]ect the efiicient.

production of a clean, dust-free and highgrade tar and of a clean, tar-free and dry of ammonia and is ofthe large crystal type and is produced with great economy of heat or steaingand with simplicity and directness in the operation of apparatus; and the invention may also-be applicable to the treatment of gas tha-tisotherwise derived from the carbonization yof coal, and mayalso have such other objects and results as are found to obtainl inl the processes hereinafter'` set forth and claimed.

, In the .accompanying drawings, Figure 1 is a conventional diagram illustrating an embodiment of the invention in a preferred arrangement of -apparatus for practising its processes; and Fig. 2l is a key to the symbols employed in the various lines that showthe connections' between' the apparatus indicated in Fig. 1.

6 indicates the producer, from which the evolved'producer-gas sses through the gtas line 7, tothc'electrica precipitator 8. e producer-gas entering this electrical precipitator is still at very high temperature, about 450 l., and its water saturation point is onlyabout 80 C.,`and therefore it is still greatly superheated in respect of its water and tar, and these, and its other vaporizable content, are carried as vapor into and through suchprecipitator 8, and said precipitator acts only to free the passing gas from dust landother solid` impurities in' its current. From said precpitator '8 the gas, with-` out having undergone appreciable cooling,

passes through the gas line 9 to the superheater 10, through which it flows in countercurrent with the `saturated air that is on the way'to theproducer. This saturated air has a temperatureof about 70 C. when it enters the said superhea'ter 10; and as a resultof the' heat interchange in passing through the superheater, the gas issues with its temperature reduced to about '280 C., and the air issues with its temperature raised to about 220 C. and at such temperature passes through the yair-line 11 to the grate of the producer 6. The partially cooled gas from the said superheater'lO passes 'through the gas line 12, still carrying itswater and tar as vapor, to the water-sprayed cooler 13, which is of the character of a cyclone precipitator and has the primary function of further coolingthe gas-to a large extent, and the incidental function of further cleaning such gas by precipitating any residue of dust or other solid impurities. A' slight amount of the tar may also be takenl out in said cooler 13 and require to be drainedv from its discharge trough 14 into the tar tank 15, the waste water from said trough lledischarging through the outlet pipe 16. But

nearly all of the tar is carried through said proaching the character of a finelyl com-4 minuted mist, will be precipitated; and the clean tar so precipitated is discharged into the tar tank 15. -The gas passesfrom said tar-precipitator 18, through the gas line 19, tothe hot acid-washer tower 20, which it enters at a temperature of about 85 C., still a little above its saturation point of 80 C; In said acid tower the ammonia is absorbed from the gas, and the ammonia-freed gas leaves vthe acid-washer at a temperature of about 82 C., still slightly above its saturation point of 80 C., the acid-solution' being kept hot by the absorption reaction, so'that there can not be any diluting of the ammonia-absorbin acid-solution that is -flowing through saigd acid-washer; and by reason of the little superheat remaining in the gas ractically no water ispicked up bythe gas '1n passing through said acid-washer, and so vthere is no precipitation of4 ammonium sulfate in said acid-washer. Thence the ammonia-fr'eed gas flows through the acid separator 21, in which it is freed of such acid'as it may carry with it, and then flows ,through the as line 22 into the first-stage final-cooler 23, t rough which it Hows in counter-current i bath;

with warm water that enters such cooler at about 50 C. In this cooler the gas is cooled to about C. and to a great extent dehydrated, and thence passes, through the gas line 24, to the second-stage final-'cooler 25, through which it passes in counter-current with cold water of about 25 C. and issues finally dehydrated and cooled to a temperature ofabout 25 C. Such clean, cool and relatively dry gas is drawn off through the gas line 26, by the exhauster 27. The main portion of such pass 2S and gas line 29-to the gas-holder 30; but a limited portion is forwarded lthrough the small reheater 31, to the ammoniasaturator 32. This saturator 32 receives the ammonia-charged acid-solution that is carried to it through the acid-line 33, from the acidtower 20. 'Ihe somewhat superheated but ammonia-freed producer-gas that flows into.

and through the saturation-bath in said satur'ator, 32, serves 'to effect the evaporation requisite to precipitate the ammonium sulfate, in the ordinary manner of such-precipitation in a saturator; and this amymonium sulfate is drawn off from thel saturator in the usual manner and passes over the drain-table`34and r into the centrifugal drier 35, from which it is discharged t0 the conveyer-belt, to be carried to the storage bin of the by-product house, and this ammonium sulfate .has the dry, clean and large crystal character, with high ammonia `content, of the high-grade'ammonium sulfate that may be derived fromA saturatorprocessing of. coke-oven gas.v The reheater 3l is required to heat the gas', from the eX- hauster 27, onlya few degrees, as at a temperature of about 35C. such gas Will carry sufficient heat into the saturator to effect the h requisite evaporation from the saturationand if a considerably greater proportion of the total dry gas, from the final coolers, is forwarded by said eXhauster to the saturator, the reheater may be cut out, through the by-pass 39, as sufficient heat will be derived from the adiabatic compression of the gas in the exhauster.

The producer gas from the producer, until it reaches the final coolers 23, 25, carries a greatamount of water-vapor and its volume 1n such superheated condition is enormously greater than after it--has been dehydrated and cooled in the final coolers. In its dried and cooled condition a far less volumeis required to pass through the saturator, even if the total dry gas is passed through, and the saturator is not required to be of impracticably large dimensions; and such gas requires only a low superhea-t when introduced into the saturator, and can not effect any dilution of the saturation-bath.

The gas put through. the saturation-bath issues from the saturator and passes through the gas-line 40, 28 tothe gas-holder and gas goes through the by- 'thence through the distribution gas-line 41.

*"Tlieacid-solution from-the drain-table 34. is received in the mother-liquor tank 42,

'which also receives, from the acid-line 33,

1s receiving heat from the absorptionA reaction 1n said acid-Washer. A continuous ciri still sufficiently heated i y t0 prevent cooling of the acid-solutlon that culation of hot acid-solution is maintained through the acid-washer and. thence lto the saturator, and back to the acid-Washer.

The aforesaid first-stage final-cooler 23 receivesits water at a. temperature of about 50 C. and discharges it at a temperature of about 80 C; and such is forced lthrough the hotWater-lin'e 52, by the hot Water pump 5'1, to the air-saturator tower 53; and from that tower the water issues cooled to a temperatureof about 50 C. and is forced through the Warm Water-line 54, by'the warm water pump 55, to the said first-stage final-cooler 23 lin which the ammonia-freed producer-gas undergoes the rst stage of its final cooling.

discharged Lhot water The air that is saturated and superheated i andI led to the gas-producer, as before mentioned, is drawn in from the outside through the fan 58 and thence is forwarded to the aforesaid air-'saturatrtower 53, which it enters at a temperature of about 25 C. In this tower 53 this air passing through the water introduced from the before-mentioned ot water-line 52, is heated and takes up --water vapor and issues saturated, at a temperature of about 70 C., andpasses through the air-line 60 to the before-mentioned superheater 10,/ through which it passesin coun-l ter-current with the hot also before mentioned, and is thereby superheated to about 220 C., and passes out vand to the producer 6 through the superheated air-line l1. A portion of the hot producergas issuing'- from the producer may be introduced into this air-line 1,1 through the by-pass 61 connecting said air-line 11 -with the primary gas-line 7, as a further control of the heat and gasification conditions in the gas-producer 6. The fresh water tank for coolers 13 and 25 is indicated at 62, and the drains from these coolers are at 16 and 63 respectively.

The processes of the/'invention may be practised in various Ways, other than the particular embodiment that has been described for purposes of illustration, and still be within the scope and subject matter of the producer-gas, as

. claims hereinafter made.

the dust and tar is a Separate invention set l:forth 1n the `application Serial No. 249,381

n filed. August 12, 1918, by Joseph van Ackmonia from producer-gas, the combination` same time herewith.

Ic1ai-m:-. v 1. In a .process for the recovery of ameren, of Pittsburgh, Pennsylvania, at the 'I of steps that consists in: absorbing the ammonia from the dust-freed and tar-freed y producer-gas by passing suchgas, at nearly i 4 saturation its Saturation temperature, through an acid- Wash; .corgveying the mother-liquor from.- such acid-Wash to a saturation-bath; cooling and dehydrating the ammonia-freed gas;

and'then-assingfsuch gas through said ath, kto effect deposition of the amdmonlum` sulfateysubstantially as specifie QIn aprocessfforthe recovery oi amproducer-gas by passing such gas,`at nearly itssaturation temperature, through an acid- Wash;- -conveying the mother-liquor` from l such acid-Washto a saturation-bath;l coolin and dehydrating the ammonia-freed gas an and then passing such portion through: said saturation-bathyto effect ,deposition4 of the ammonium sulfate; substantially as y, specif- Hed. v

In aprocess for the recovery ofl tar and ammonia from producer-gas, thecombination of steps thatconsists in: electrically precipitating the y dust from y the hot gasv y from the'producer; then passing said vgas 1n I i through 'an acid-Wash to vabsorb the am-V .'monia; conveying the mother-liquor from counter-curren with the air going to the thenorfurther coolingV and cally precipitating the residue of the tar fromlsuchf'partially cooled but still hot gas; then .passing such still hot and tar-'freed gas the acid-wash to a saturation-bath; passing the ammonia-freed gas through iin-al cooling and dehydrating stages and thence partly to the gas-holder andxpartly to and through a rheating 'operationand then passing such relie-ated portion of the gas through said' saturation-bath, to cect deposition of .the

ammonium sulfate; withdrawing and draining the aminonium sulfate and returning the liquor ronrsuch draining, with addition of.

-1esh"acid, to the acid-Wash; heating and satuating the air', on its lWay to its afore- .said superheating,.l by passing such air in counter-current with the hotv water from 'A theirst stage ofthe aforesaid final cooling of the gas; and conveying the waterfrom "said air heating operation back to the first stage of the final gas-cooling; and conveying substantially to preclude deposition of ammonium sulfate in said acid-solution; conducting the ammonla-charged acid-solution into -a saturation-bath; cooling and dehydrating the ammonia-freed gas; and then forcing a portion of said gas throu h such saturation-bath, with` enough super eat to effect deposition of the ammonium sulfate; substantially as specified. y. ,Y

5. In a process for the recovery of tar and ammonia. from producer-gas, the combination of steps that consists in: extracting the tar whilethe gas is superheated; absorbing the ammoniafrom the tar-freed gas by lpassingsaid gas through an acid-solution at a temperature sufficiently above the saturation point of ther-gas substantially to prethen somewhat reheating a portion of it.;

tion into a ysaturation-bath; cooling and dehydrating theammonia-freed gas; and then lforcing al portion of said gas lthrough such saturation-bath, with `enough superheat to effect depositionof thev ammonium sulfate;

substantially as'specified. producer, to superheat said-air and partially cool said "gasg washing saidgaswith water; then electri- G. In a process for the recovery of ammonia from producer-gas, the combination.

' preclude deposition of ammonium sulfate 1n said acid-solution ;,conducting the ammoniacharged acid-solution' into a saturation-bath;

cooling and -dehydratingthe ammonia-freed gas; and then forcing,r a portion of said-,gas through such saturation-bath with enough superheat to effect deposition of the ammonium sulfate; and maintaining said acidsolution, kept hot by the absorption reaction, in circulation and recirculation through its anmmoni'a-absorptionv and sulfate-deposition stages, with additionof fresh acidto its current; vsubstantially as specified.

'7.- In a process, for the recoveryv of amconducting the ammonia-charged acid-sol-umonia from-,ammonia-charged gas, thecombinatibn of steps that consists in: absorbing the ammonia from the dust-freed and tarfreed gas by passing such gas, at nearly its saturation temperature, through an acidwash conveying the mother-liquor from such acid-wash to a. saturation-bath; cooling and 5 dehydrating the ammonia-freed gas; and then being effected with l passing such gas through said saturationthe ammonia from thedust-freed and tar-` v freed gas by passing such gas, at nearly its saturation temperature, through an acidwash; conveying the mother-liquor from such acid-Wash to a saturation-bath; cooling and dehydrating the ammonia-freed gas and then somewhatreheating a portion of it; and then passing such portion through said .saturation-bath, to eilect deposition of the ammonium sulfate; the recovery of ammonlum sulfate being effected with the passing of' a reduced volume of gas, relatively low in heat, through a saturation-bathof reand stricted volume; substantially as specified.

In a process for the recovery -of ammonia from, ammonia-charged gas, the combination of steps that. consistsl in: absorbing the ammonia from the tar-freed gas by passing-said gas through an acid-solution at a 'temperature suliciently above the saturation-point of the gas substantially to prei clude diluting of said solution and yet at a temperature near enough said saturations point substantially to precludedeposition of ammonium sulfate in said acid-solution; conducting the ammonia-charged acid-solution into a saturation-bath; cooling and dehydrating the ammonia-freed gas; and then forcing a portion of said gas throu h such saturation-bath, with enough super eat to eiiect deposition of the ammonium sulfate; the recovery of ammonium sulfate being effected with the passing of Va reduced of gas, relatively low in heat, through a saturation-bath of restricted volume; substantially as specified. y l

In a process for therecovery of tar l ammonia from I.ammonia-charged gas', the combination of steps Ithat consists in: extracting the tar While the gas is supertarffreed gas by passing said gas through an acid-solution at a temperature suiiciently above the saturation point of the gas substantially to preclude diluting of said solution and yet lat a temperature near enough fheated; absorbing the ammonia. from -the v monium sulfate; the y K sulfate 'being effected with the passing of av volume v said saturation-point substantially to preclude deposition of ammonium sulfate in said acid-solution; conducting the ammoniasuperheatl to effect deposltion 'of the amrecovery of ammonium reduced volume of gas, relatively -low in heat, through a saturation-bath of restricted volume; substantially as specified.

11. In a process for the'recovery of ammonia from ammonia-charged gas, the combinatonof :steps that the ammonia fromthe tar-freed gasby passing said gas through an acidsolution at a. temperature sufficiently above the saturation-point of fthe` gas substantially to preclude diluting of said solution and yet at a temperature near enough said saturation# point substantial-ly to preclude deposition of ammonium sulfate in said acid-solution; conducting the tion into a saturation-bath; cooling and dehydrating the ammonia-freed gas, and then forcing a portion of said gas through such saturation-bath,` With enough superheat tok effect deposition of the ammonium sulfate; and maintaining said acid-solution, kept hot by the absorption reaction, in circulation and recirculation through its ammonia-aibsorption andsulfate-deposition stages, with addition of freshacid to its' current; the recovery of ammonium sulfate being eii'ected with the passing of Ia reduced volume of gas, relatively -loW in heat, through a saturation-bath of restricted ,volume; substantially' as specified.

12. In a process for the recovery of tar andpammonia from ammonia-charged gas,

, the combina-tion of steps that consists in:

extracting the tar from the ammonia-charged gas hot; passing such hot gas through Van acid-wash to absorb the ammonia of the gas; discharging the mother-liquor from such acid-Wash into a saturatiombath; passing the tar-freed and ammonia-.freed gas through a cooling and dehydrating operation; and` passing such gas through such saturationbath 'to eiiect deposition of the ammonium sulfate; substantially as specified.

In testimony whereof, I hereunto set my hand in the presence of two subscribing Witnesses. v

Jos'ErH BECKER. Witnesses:

HENRY Love CLARKE, JOSEPH DvonAK.

ammonia-charged 'acid-solu consists in: absorbing roo 

